1. Field of the Invention
The present invention relates to a back light module. More particularly, the present invention relates to a back light module capable of reducing damage to the linear light source thereof by the impact of the light guide plate during the impact test.
2. Description of Related Art
With the advancement of information technology, the personal computer is developing toward portable notebook computer as the portable notebook computer provides convenience of portability and access to information. Therefore the notebook computer is highly attractive to a variety of people for business, correspondence, research, entertainment and the like. Different types of the portable notebook computers have been extensively developed in order to meet various needs of users.
Generally, in order to ensure the quality of the notebook computer such as operation and stability under various conditions, prior to shipping out to the warehouse for storage, the notebook computer are being subjected to a plurality of tests during various manufacturing stages. As for impact test, as the reflective mask for light is difficult to firmly fix the light, and therefore the light guide plate may easily get displaced and because it is positioned proximate to the linear light source, and therefore the displacement of the light guide plate towards the linear light source may damage the linear light source. One conventional solution for resolving the above problem is to form an ear portion 131a on the light guide plate 131 and a protrusion portion 110a on the frame 110 (as shown in FIG. 1A) such that the ear portion 131a of the light guide plate 131 is locked onto the protrusion portion 110a of the frame 110 to prevent displacement of the light guide plate 131 toward the linear light source (not shown) during the impact test.
However, in order to increase the efficiency of the light guide plate, a plurality of V-shaped notches are formed on the surface of the light guide plate. However, as the ear portion may interfere with V-shaped notches, therefore the aforementioned technique of securing the light guide plate to the frame is not suitable for the light guide plate with V-shaped notches.
To resolve the aforementioned problem, another conventional solution is described as follows. FIG. 1B is a perspective schematic view of a portion of a conventional back light module. FIG. 1C is a schematic view of a guide light plate positioned using a double sided tape on a frame of the conventional back light module. Referring to FIGS. 1B and 1C, the conventional back light module comprises a frame 110, a reflective mask 120, a light guide plate 130 and a linear light source (not shown), wherein the reflective mask 120 is installed in the frame 110. The light guide plate 130 has a light incidence side 132 lodged into the reflective mask 120. The linear light source (not shown) is installed between the light incidence side 132 of the light guide plate 130 and the reflective mask 120.
In order to resolve the aforementioned problem, the light guide plate 130 therein is resisted from being displaced. The light guide plate 130 can be firmly fixed on the reflective mask 120 and the guide light plate 130 can be attached to the frame 110 using a double sided tape 140 (as shown in FIG. 1C) to resist the guide light plate 130 from displacing from the reflective mask 120. However, securing strength using the reflective mask 120 to hold the light guide plate 130 and using the double sided tape 140 to attach the reflective mask 120 to the frame 110 is not adequate, and during the impact test, the light guide plate 130 come loose from the reflective mask 120 and damage the linear light source.